Tolerance and adaptation mechanisms developed by Moringa oleifera (L) seeds under oxidative stress induced by salt stress during in vitro germination

The current study explores the capacity of Moringa oleifera (L), to overcome and/or tolerate oxidative stress induced by a saline substrate as a constraining factor. For this, Moringa seeds have been subjected, for 15 days after germination in vitro, with increasing concentrations of NaCl, and specifically at 0 (control), 5, 7.5, 10, 12.5 and 15g l(-1). Both morpho-physiological and biochemical aspects were evaluated which were considered as probable indicators of tolerance or sensitivity to this stress. Our results reveal an increased synthesis of proline, lipids, proteins, CAT, GPX, APX, flavonoids, condensed tannins and a decrease in total polyphenols (-29.97%), mainly due to their high carbon cost. The degradation state of the cell membranes was evaluated by the MDA assay, which increased by 91.25%. On the contrary, the oxidative damage caused by Reactive Oxidative Species (ROS), detected by H2O2, decreased by 37.89%. The germinative ability of the seeds was affected indicating moderate resistance to stress as it was evaluated by the development of epicotyledonary axes, even under 15 g l(-1) of NaCl without showing symptoms of stress or sensitivity. This result supports our hypothesis on the ability of the species to maintain or even improve its oxidative status.